If you’re a fan of the History Channel, you’ll feel right at home watching Robert Redford’s recreation of Abraham Lincoln’s murder near the beginning of The Conspirator. Many of that channel’s programs feature, between the talking heads of historians, speedy montages of the events under discussion. There’s no need for dialogue or acting since fast editing, simple pantomime, and loud music do all the work. As is the case here: thundering hoofbeats as John Wilkes Booth rides up to Ford’s Theatre; a close-up of reins flung to a stable hand. Then the camera takes on the point of view of the assassin as he mounts winding stairs and negotiates corridors on his way to the presidential box. Much crosscutting between that and the secretary of state’s house, as another conspirator attempts to murder William Seward. Then we zoom in on Booth’s derringer aimed at Lincoln’s head. The shot rings out. A flurry of images as Booth escapes—Sic semper tyrannis!—more thundering hoofs, newspaper headlines, roundup of conspirators, swelling music, the army’s pursuit of Booth, the burning barn, a sniper taking aim, Booth goes down, more headlines, music swelling to a climax. Phew! It’s the Morse code of filmmaking.

But then The Conspirator calms down into a political drama featuring plenty of dialogue and conventional dramatic confrontations. The script by Gregory Bernstein and James D. Solomon takes as its protagonist the young lawyer-soldier Frederick Aiken, appointed to defend Mary Surratt, the landlady of the boardinghouse in which the intriguers (including Mary’s son, John) met and planned. We are privy to Aiken’s resentment at having to defend someone he believes guilty, to his frustration with the legal obstacles (less than twenty-four hours to prepare, a military tribunal precommitted to a guilty verdict, Mrs. Surratt prohibited from testifying), and finally to his outrage at the way Secretary of War Edwin Stanton undermines the Constitution in order to put heads into nooses.

One feels obligated (overly obligated) to applaud The Conspirator’s current political relevance. The injustice done to Mrs. Surratt (not the verdict per se but the way it was reached) echoes the current legal scandal of Guantánamo, and some of the parallels are truly striking (including the way Surratt’s Catholicism may have aggravated prejudice just as some Americans’ ignorance of Islam may have fueled animosity toward innocent Muslims after 9/11). It’s not hard to imagine Redford and the scriptwriters pressing on President Barack Obama the Santayana maxim about those forgetting history being condemned to repeat it. Yet the Surratt affair took place within a specific, not quite repeatable historical context and involved people of absolutely unrepeatable individuality, and unless that context and those characters are brought home to the viewer in all their specificity and individuality, any political example the Surratt case presents may seem strained and the film’s power as a work of art undermined. In short, this movie is immediately worthy, but does it ultimately convince as a drama about humanity coerced by political power?

Aiken’s main antagonist is not the trial’s prosecutor but Secretary Stanton, who holds that the state of the Union, with not every Confederate army disbanded and chaos still a possibility, demands a swift and final resolution that will bring what we nowadays call “closure.” If there is any truth to Stanton’s claim, then we have not a clash of simple right against simple wrong but two rights in conflict (constitutional rights vs. sheer survival). But how can we judge Stanton’s claim when the script confines our view of events strictly to a Washington, D.C., that seems strangely peaceful? At one point a rock is heaved through the Surratt boardinghouse window, but one instance of violence doesn’t betoken national unrest. What’s happening in the rest of the country? Vigilante mobs? Violence-inciting rumors? Confederates still armed and organizing an attack? Just when the movie needs a History Channel montage, none is forthcoming.

Or are we meant to regard Stanton as some sort of paranoid would-be tyrant who fears an upheaval that doesn’t exist? Stanton has been the object of much hostile scrutiny by historians, so this would have been a distinct possibility for the filmmakers to pursue. Yet nothing in the script or Kevin Kline’s rather enervated performance suggests anything so sinister.

With the historical context so little emphasized, dramatic impact must come from the characterizations. And the one real success of The Conspirator is in its presentation of Mary Surratt as a sphinx with a secret her lawyer cannot unearth. Is she a loving mother shielding a guilty son (still a fugitive) or a convinced rebel who enabled the president’s murder? Is her unforthcoming manner a sign of contempt, a noble stoicism, or a cloak of guilt? Robin Wright brings a raw-boned, ascetic beauty to the role and a way of uttering her dialogue that keeps both her lawyer and the audience shuttling between exasperation and respect. Hers is one of the two best performances in the picture, the other being Colm Meaney’s portrayal of General David Hunter, head of the military tribunal, as a quietly ferocious yet dignified bulldog.

But the true protagonist of The Conspirator isn’t Surratt; it’s her lawyer. The script traces his inner journey from initial distaste for his client to an ardent desire to get a fair trial for Surratt, whether she’s guilty or not. Schematically, the role fulfills its function to make us perceive injustice, and actor James McAvoy makes a fair showing of pluck and intelligence, yet I was left with an impression that Frederick Aiken remained a mouthpiece for the filmmakers rather than a full-blown character. A fatal economy vitiates the script. For instance, late in the story, an emotionally exhausted Mary seems ready to open up to Aiken, not necessarily with information but more likely to unload some personal burden, and she invites him to take a walk with her around the prison yard. What was then shared between lawyer and client during the walk might have deepened the drama, but Redford simply drops the matter and cuts away to a completely different incident. The law must respect lawyer-client confidentiality, but why should Redford? Whether Aiken is with Surratt or his disapproving fiancée or his drinking buddies or persons of state, his dialogue always fulfills the requirements of the scene but gives us no incidental detail that would let the character, and the movie, breathe.

Still, Redford does create some visually telling moments. When Mary’s daughter testifies, the prosecutor orders guards to stand between her and Mrs. Surratt, and the staging makes us feel the girl’s isolation and mounting panic. The execution scene is hauntingly done, with the camera noticing the very last things the condemned will ever see: the newly made coffins piled near the scaffold, a rosary dangling from a priest’s hand, the awed stare of a boy drummer getting ready to beat the tattoo when the trap door of the gallows drops, the courtesy of the soldier who opens an umbrella to shield Mary’s eyes from the sun’s glare. All this shows the mastery of a director who needs a complex script to release his full powers, such as the one Paul Attanasio provided for Redford’s Quiz Show (1994). In that film every scene opened up a range of possibilities within the characters and made us gratifyingly aware of how many sinkholes the road of life contains. The Conspirator cleanly scores a number of political points but never rises to the level of powerful political art.